The WMI HDD Health sensor connects to the parent device via Windows Management Instrumentation (WMI) and monitors the health of integrated development environment (IDE) disk drives on the target system using Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T.).

WMI HDD Health Sensor

WMI HDD Health Sensor

i_square_cyanFor a detailed list and descriptions of the channels that this sensor can show, see section Channel List.

Sensor in Other Languages

  • Dutch: WMI HDD Status
  • French: État du disque dur (WMI)
  • German: WMI Laufwerkszustand
  • Japanese: WMI HDD 正常性
  • Portuguese: Funcionamento do HDD (WMI)
  • Russian: Работоспособность жесткого диска WMI
  • Simplified Chinese: WMI 硬盘健康状况
  • Spanish: Salud HDD (WMI)


  • This sensor requires at least Windows 7 on the target system that holds the hard disk drives you want to monitor. The sensor might not work reliably if the target system runs on Windows 2003, Windows XP, or Windows Vista. Because of a known bug in those systems, the sensor might not detect available hard disk drives.
  • This sensor requires WoW64 (Windows 32-bit on Windows 64-bit) for target systems that run Windows Server 2016.
  • This sensor requires credentials for Windows systems in the settings of the parent device.
  • This sensor only supports IPv4.
  • This sensor has a medium performance impact.
  • The values that this sensor shows can vary depending on how a vendor handles S.M.A.R.T. values. See the respective vendor's documentation for more information.
  • The items in the list in the Add Sensor dialog are specific to the parent device.

i_podYou cannot add this sensor to the hosted probe of a PRTG Hosted Monitor instance. If you want to use this sensor, add it to a remote probe device.

Basic Sensor Settings

Basic Sensor Settings

Basic Sensor Settings



Sensor Name

Enter a name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets.

i_round_blueIf the name contains angle brackets (<>), PRTG replaces them with braces ({}) for security reasons. For more information, see the Knowledge Base: What security features does PRTG include?

Parent Tags

The tags that the sensor inherits from its parent device, parent group, and parent probe.

i_round_blueThis setting is for your information only. You cannot change it.


Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.

i_round_blueIt is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).

i_round_blueFor performance reasons, it can take some minutes until you can filter for new tags that you added.

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

  • smartsensor


Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority (i_priority_1) to the highest priority (i_priority_5).

S.M.A.R.T. Specific

S.M.A.R.T. Specific

S.M.A.R.T. Specific



Serial Number

The serial number of the disk that this sensor monitors.

Size (GB)

The size of the disk that this sensor monitors.


The name of the disk that this sensor monitors.

Timeout (Sec.)

Enter a timeout in seconds for the request. Enter an integer. The maximum timeout value is 900 seconds (15 minutes).

i_round_blueIf the reply takes longer than this value, the sensor cancels the request and shows a corresponding error message.

Debug Options

Debug Options

Debug Options



Result Handling

Define what PRTG does with the sensor result:

  • Discard result: Do not store the sensor result.
  • Store result: Store the last sensor result in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file name is Result of Sensor [ID].Data.txt. This setting is for debugging purposes. PRTG overwrites this file with each scanning interval.

i_round_blueIn a cluster, PRTG stores the result in the PRTG data directory of the master node.

Sensor Display

Sensor Display

Sensor Display



Primary Channel

Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.

i_round_blueYou can set a different primary channel later by clicking b_channel_primary below a channel gauge on the sensor's Overview tab.

Graph Type

Define how different channels are shown for this sensor:

  • Show channels independently (default): Show a graph for each channel.
  • Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This generates a graph that visualizes the different components of your total traffic.
    i_round_redYou cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).

Stack Unit

This setting is only visible if you select Stack channels on top of each other above.

Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.

Inherited Settings

By default, all of these settings are inherited from objects that are higher in the hierarchy. We recommend that you change them centrally in the root group settings if necessary. To change a setting for this object only, click b_inherited_enabled under the corresponding setting name to disable the inheritance and to display its options.

i_square_cyanFor more information, see section Inheritance of Settings.

Scanning Interval

Scanning Interval

Scanning Interval

i_square_cyanFor more information, see section Root Group Settings, section Scanning Interval.

Schedules, Dependencies, and Maintenance Window

i_round_blueYou cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.

Schedules, Dependencies, and Maintenance Window

Schedules, Dependencies, and Maintenance Window

i_square_cyanFor more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.

Access Rights

Access Rights

Access Rights

i_square_cyanFor more information, see section Root Group Settings, section Access Rights.

Channel List

i_round_blueWhich channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.

The channel names indicate the ID of the S.M.A.R.T. attribute, followed by a colon, and the typical meaning of the channel. The sensor can also show other attributes that the target device returns, but some channels have the name Unknown Channel. This happens if PRTG cannot match the ID of a found attribute with an internally defined channel name.

i_round_redSome vendors do not agree on attribute definitions and define meanings other than the common ones.

Every attribute of a disk assumes a value. PRTG shows these attributes as channels with their last, minimum, and maximum value. These channel values change over time and indicate the disk health. Higher values correspond to a better health. The disk's attributes come with a threshold, defined by the manufacturer of the drive. If a channel value is lower than this threshold, the sensor automatically shows the Warning status. This indicates that the S.M.A.R.T. status of the HDD might break soon.

i_round_blueFor some attributes, there are no thresholds defined and because of this, they cannot be categorized for a status other than the Up status. You can define lookups and use them with affected channels to get the desired status for a return value.



Average Erase Count And Maximum Erase Count

The average erase count and the maximum erase count

Command Timeout

The command timeout count


In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status

Erase Fail Count

The erase fail count

G-Sense Error Rate

The G-sense error rate count

Hardware ECC Recovered

The hardware ECC recovered count

Power Cycle Count

The power cycle count

Power Loss Protection Failure

The power loss protection failure count

Power-On Hours

The power-on hours count

Program Fail Count Total

The program fail count total

Read Error Rate

The read error rate count

i_round_blueThis channel is the primary channel by default.

Read Error Retry Rate

The read error retry rate count

Reallocated Sectors Count

The reallocated sectors count

Reported Uncorrectable Errors

The reported uncorrectable errors count

SATA Downshift Error Count

The SATA downshift error count

Soft ECC Correction

The soft ECC correction count

Soft Read Error Rate

The soft read error rate count

SSD Erase Fail Count

The SSD erase fail count

SSD Life Left

The SSD life left count

SSD Program Fail Count

The SSD program fail count

Unexpected Power Loss Count

The unexpected power loss count

Unknown Channel

PRTG cannot match the ID of a found attribute with an internally defined channel name

Unused Reserved Block Count Total

The total unused reserved block count

Used Reserved Block Count Total

The total used reserved block count

Temperature Celsius

The temperature

Total LBAs Read

The total LBAs read

Total LBAs Written

The total LBAs written

Wear Range Delta

The wear range delta


i_square_blueKNOWLEDGE BASE

What security features does PRTG include?

My WMI sensors don't work. What can I do?